Update description in actions.yaml (#375)

## Issue
Fixes #316. This PR sets the correct description message in the
`get-password` action of actions.yaml

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Co-authored-by: Mehdi Bendriss <bendrissmehdi@gmail.com>

actions.yaml

@@ -5,8 +5,8 @@ get-primary:
   description: Report primary replica
 
 get-password:
-  description: Change the admin user's password, which is used by charm.
-    It is for internal charm users and SHOULD NOT be used by applications.
+  description: Fetch the password of the provided internal user of the charm, used for internal charm operations. 
+    It is for internal charm users only, and SHOULD NOT be used by applications.
   params:
     username:
       type: string